Glass-run for window glass of motor car

ABSTRACT

A glass-run for a window glass moving to open and close of a motor car, which has excellent abrasion resistance, is disclosed, said glass-run comprising a substrate of a high molecular material having coated on the surface thereof a film formed by hardening a specific paint composition comprising components (A), (B), (C), (D) and (E) described in the specification.

FIELD OF THE INVENTION

The present invention relates to a novel glass-run for a window glass ofa motor car, more specifically to a glass-run for a window glass of amotor car, having improved abrasion resistance.

BACKGROUND OF THE INVENTION

Glass-run for a window glass of a motor car has been required variousproperties (such as high heat resistance and weather fastness) to beexhibited under severe conditions. In general, glass-run applied to thewindow of motor car, when it is used to support the window glass,especially in the case of a window glass moving to open and close, isrequired to be made of materials having a low coefficient of friction.The glass-run is used at the parts to be contacted with the movableglass, while a fixed window glass is supported by window flame per se,that is, by weather strips made of rubber or plastics. The glass-run isgenerally coated with a film at the parts to be contacted with themovable glass. However, an abrasion resistance test of such aconventional glass-run reveals that the coated film per se is easilyabraded or cracked, or the coated film is often peeled apart from thesubstrate.

SUMMARY OF THE INVENTION

An object of this invention is to provide a glass-run for a window glassof a motor car, which has excellent abrasion resistance.

As a result of extensive studies on glass-run to improve its abrasionresistance, it has now been found that the coated film is thedeterminative factor on the abrasion resistance of glass-run and thatthe abrasion resistance can be markedly improved by coating a paintcomposition comprising the following components (A), (B), (C), (D) and(E) on at least a part of the surface of a substrate of glass-run to becontacted with the movable window glass, and hardening it.

That is, the present invention provides a glass-run for a window glassmoving to open and close of a motor car, which comprises a substrate ofa high molecular material having a film coated on at least a part of thesurface of the substrate to be contacted with the window glass, saidfilm being formed by hardening a paint composition comprising:

(A) 100 parts by weight of an urethane prepolymer obtained by thereaction of a polyester polyol having hydroxy groups in its terminal anda molecular weight of 1,000 to 3,000, synthesized from a saturated diolhaving 2 to 6 carbon atoms and an orgnaic dicarboxylic acid having 4 to6 carbon atoms, with an organic diisocyanate in the molar ratio ofNCO/OH of from 0.6/1 to 0.95/1;

(B) 10 to 60 parts by weight of a castor oil polyol;

(C) 1 to 100 parts by weight of an urethane prepolymer having isocyanategroups in its terminal obtained by the reaction of a low molecularpolyol and an organic diisocyanate;

(D) 2 to 100 parts by weight a fluoro resin; and

(E) 5 to 100 parts by weight of a silicone oil.

Furthermore, the present invention provides the glass-run wherein thepaint composition further comprises (F) 0.5 to 3 parts by weight oftalc.

DETAILED DESCRIPTION OF THE INVENTION

High molecular materials which can be used as a substrate of glass-runare not particularly limited, and any materials conventionally used asthe substrate of glass-run can be used in the present invention. Thesurface of the substrate is coated with the paint composition of thepresent invention. The surface of the substrate is optionally cleaned upbefore coating the paint composition.

The urethane prepolymer (A) which is one of the components of the paintcomposition is obtained by the reaction of a polyester polyol and anorganic diisocyanate in the molar ratio of NCO/OH of from 0.6/1 to0.95/1. When the ratio is outside the above range, the resultingglass-run does not exhibit excellent abrasion resistance in a hightemperature atmosphere.

The polyesterpolyol which constitutes the urethane prepolymer (A) hashydroxy groups in its terminal and a molecular weight of from 1,000 to3,000 and is obtained by reacting a saturated diol having 2 to 6 carbonatoms and an organic dicarboxylic acid having 4 to 6 carbon atoms.Examples of saturated diols include propylene glycol, buthanediol,penthanediol, hexanediol and the like, and examples of organicdicarboxylic acids include adipic acid, succinic acid and the like.

Examples of orgnaic diisocyanates which constitutes the urethaneprepolymer (A) include 4,4'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate and the like.

The castor oil polyol (B) is a copolymer composed of castor oil,phthalic anhydride and glycerol, and the molecular weight and number ofOH groups of castor oil polyol may be changed by altering the molarratio of the three monomer components. The number of OH group isgenerally more or less 100.

The urethane prepolymer (C) has isoyanate groups in its terminal and isobtained by reacting a low molecular polyol (generally a molecularweight of less than 1,000) and an organic diisocyanate. Examples of lowmolecular polyols include glycerine, trimethylol propane and the like.As the organic diisocyanate, those described in the preparation of theurethane prepolymer (A) can be used.

Examples of the fluoro resin (D) include 4-fluoroethylene resin,4-fluoroethylene/6-fluoropropylene copolymer, 3-fluoro-chloro-ethyleneresin, fluorovinlydene resin and the like.

Examples of the silicone oil (E) include dimethyl silicone oil, methylchloro silicone oil, methyl hydrogen silicone oil, methyl phenylsilicone oil, fluoro silicone oil and the like.

In the paint composition used in the present invention, component (B) isused in an amount of 10 to 60 parts by weight per 100 parts by weight ofcomponent (A). When component (B) is used in an amount outside the aboverange, the abrasion resistance of the resulting glass-run isdeteriorated. Component (D) is used in an amount of 2 to 100 parts byweight, preferably 10 to 60 parts by weight, per 100 parts by weight ofcomponent (A). The use of less than 2 parts by weight of component (D)results in deterioration of the abrasion resistance and the use of morethan 100 parts by weight of component (D) degrades the stability of thepaint composition and precipitations of component (D) occurssignificantly. Component (E)is used in an amount of 5 to 100 parts byweight, preferably 10 to 50 parts by weight, per 100 parts by weight ofcomponent (A). When it is less than 5 parts by weight, the abrasionresistance of the resulting glass-run is degraded, and when it is morethan 100 parts by weight, the resulting paint composition becomesunstable and component (E) is separated from the composition as well asin the case of component (D).

In the preparation of the paint composition, a catalyst capable ofaccelating the urethanizating reaction may also be added, such asdibuthyltin diacetate, dibuthyltin dioctoate, dibuthyltin dilaurate,dibuthyltin diesterate, tributhyltin acetate, tributhyltin octoate,tributhyltin laurate, dioctyltin diacetate, dioctyltin dilaurate,diethyltin oleate, monomethyltin dioleate, etc. In addition, fillerssuch as carbon black, silicon dioxide etc. may further be added.

Organic solvents which can be used as a diluent for the paintcomposition include acetone, methyl ethylketone, methyl isobuthylketone, benzene, toluene, xylene, ethyl acetate, methyl acetate,isopropyl acetate, trichloroethylene, 1,1,1-trichloroethane,dimethylformamide etc. The amount of organic solvents may be selected inaccordance with a desired viscosity of the composition used forproccessing.

As coating method for the paint composition used in the production ofglass-run, dip coating method, spray coating method, brush coatingmethod, knife coating, roller coating etc. can be used, but the coatingmethod is not limited thereto. The paint composition is used in the formof a solution diluted with the organic solvent as described above. Thepaint ccmposition is coated on the substrate to form a firm generallyhaving a dry thickness of from 10 to 100 μm and preferably from 30 to 50μm.

The production of glass-run according to the present invention has anadvantage that a film having excellent properties with respect toabrasion resistance, nonadhesion property, water-repellancy andlubricity can be formed on the substrate by a simple operation, i.e.,merely by coating and allowing to stand at a room temperature forseveral hours or heating at 180° C. or the less for several minutes. Theterm "room temperature" herein means a normal temperature in the roomaffected from usual climate and without using heating means such asdryer and hearth. The coated film is preferably hardened at a roomtemperature since a heating apparatus is not required and the operationis simplified. However, heating means may be used when a great deal ofthe treatment is required. In the case, the temperature must bemaintained below 180° C. because the heating at a temperature of morethan 180° C. might deteriorate the substrate. Some kinds of substrateare softened at a temperature of more than 100° C., and therefore it ispreferred to treat it by heating at a temperature of less than 100° C.The heating means may properly be selected.

The present invention will be described in more detail by reference tothe following Examples. In the Examples, all parts are by weight, withregard to the substrates used in Examples, EPDM rubber (hardness JIS, A80 degree) was used in Example 1-8 and an extruded product of a mixtureof polyvinyl chloride (100 parts), dioctyl phtalate (75 parts), bariumstearate (2 parts), zinc stearate (1 part) and dibuthyltin dilaurate (1part) (the extrusion temperature: 130°-140° C.) was used in Example 9.

Urethane prepolymer (A) and urethane prepolymer (C) employed in Exampleswere prepared in the following manner.

Urethane prepolymer (A) having terminal hydroxy groups was obtained byreacting 1000 parts of polyester polyol(hydroxy group value: 56.0)synthetized from 1,4-buthanediol and adipic acid, and 100 parts of4,4'-diphenylmethane diisocyanate (MDI), in 2000 parts of toluene underdryed nitrogen atmosphere at 80° C. for 3 hours.

Urethane prepolymer (C) having terminal NCO groups was obtained byreacting 100 parts of trimethylolpropane and 553 parts of4,4'-diphenylmethane diisocyanate in 487 parts of ethyl acetate underdryed nitrogen atmosphere at 80° C. for 3 hours.

EXAMPLE 1

25.0 parts of urethane prepolymer (A), 3.5 parts of castor oil polyol("2310-50T" made by Tokushima Seiyu Co., Ltd.), 10 parts of urethaneprepolymer (C), 8.0 parts of 4-fluoroethylene resin, 8.0 parts ofsilicone oil, 0.5 part of carbon black, 0.065 part of dibuthyltindilaurate, 0.065 part of phenol salt of 1,8-diazabicycloundecene-7, weremixed using a solvent consisting of 1.3 parts of toluene, 3.0 parts ofcyclohexanone, 15.0 parts of tetrachloroethylene and 118.9 part oftrichloroethylene, to prepare a paint composition. This paintcomposition was coated on a substrate and hardened to produce aglass-run for a window glass of motor car.

Abrasion resistance of the product was examined by an abrasionresistance test, and the results are shown in the Table.

ABRASION RESISTANCE TEST

The coated surface of the product was abraded by moving the glassabrasor (thickness: 5 mm) in reciprocal manner under the followingcohditions.

Charged weight: 3 kg

Cycle of abrasor: 60 times/ minute

stroke of abrasor: 145 mm

EXAMPLES 2-9 AND COMPARATIVE EXAMPLES 1-2

Experiments were carried out in the same manner as in Example 1 exceptusing the paint composition shown in the Table, and the results are alsoshown in the Table.

                                      TABLE                                       __________________________________________________________________________                 Comp.                                                                             Comp.                                                                     Ex. 1                                                                             Ex. 2                                                                             Ex. 1                                                                             Ex. 2                                                                             Ex. 3                                                                             Ex. 4                                                                             Ex. 5                                                                             Ex. 6                                                                             Ex. 7                                                                             Ex. 8                                                                             Ex.                      __________________________________________________________________________                                                         9                        Urethane prepolymer (A)                                                                    25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                                                                              25.0                     Castor oil polyol (1)                                                                      --  --  3.5 6.0 8.0 10.0                                                                              --  --  8.0 8.0 8.0                      Castor oil polyol (2)                                                                      --  --  --  --  --  --  8.0 --  --  --  --                       Castor oil polyol (3)                                                                      --  --  --  --  --  --  --  8.0 --  --  --                       Urethane prepolymer (C)                                                                    14.0                                                                              14.0                                                                              10.0                                                                              10.0                                                                              10.0                                                                              10.0                                                                              14.0                                                                              10.0                                                                              10.0                                                                              10.0                                                                              10.0                     Fluoro resin 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0                      Silicone oil 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0                      Carbon black 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5                      Talc         --  1.0 --  --  --  --  --  --  1.0 2.0 --                       DBTDL        0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                    SA No. 1     0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                                                                             0.065                    Toluene      1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3                      Cyclohexane  3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0                      Tetrachloroethylene                                                                        15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                                                                              15.0                     Trichloroethylene                                                                          118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                                                                             118.9                    Abrasion resistance (time)                                                                 5000                                                                              5000                                                                              10,000                                                                            20,000                                                                            25,000                                                                            10,000                                                                            10,000                                                                            15,000                                                                            45,000                                                                            30,000                                                                            50,000                   __________________________________________________________________________     [Notes]-                                                                      Castor oil polyol (1): hydroxy group value, 80; "231050T" made by             Tokushima Seiyu Co., Ltd. Japan                                               Castor oil polyol (2): hydroxy group value, 86; "230850T" made by             Tokushima Seiyu Co., Ltd. Japan                                               Castor oil polyol (3): hydroxy group value, 92; "231160T" made by             Tokushima Seiyu Co., Ltd. Japan                                               DBTDL: dibuthyltin dilaurate                                                  SA No. 1: phenol salt of 1,8diazabicycloundecene-7                       

It can be seen from the results that the glass-run of the presentinvention has markedly improved abrasion resistance.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. A glass-run for a window glass moving to open andclose of a motor car, which comprises a substrate material having a filmcoated on at least a part of the surface of the substrate to becontacted with the window glass, said film being formed by hardening apaint composition comprising:(A) 100 parts by weight of an urethaneprepolymer obtained by the reaction of a polyester polyol having hydroxygroups in its terminal and a molecular weight of 1,000 to 3,000,synthesized from a saturated diol having 2 to 6 carbon atoms and anorganic dicarboxylic acid having 4 to 6 carbon atoms, with an organicdiisocyanate in the molar ratio of NCO/OH of from 0.6/1 to 0.95/1; (B)10 to 60 parts by weight of a castor oil polyol; (C) 1 to 100 parts byweight of an urethane prepolymer having isocyanate groups in itsterminal obtained by the reaction of a low molecular polyol and anorganic diisocyanate; (D) 2 to 100 parts by weight of a fluoro resin;and (E) 5 to 100 parts by weight of a silicone oil.
 2. A glass-run asclaimed in claim 1, wherein said paint composition further comprises (F)0.5 to 3 parts by weight of talc.